Hawaii’s Youngest Submarine Volcano
Lo`ihi Seamount is an active volcano built on the seafloor south of Kilauea about 30 km from shore. The seamount rises to 969 m below sea level and generates frequent earthquake swarms, the most intense of which occurred in 1996. An eruption at Lo`ihi has yet to be observed, but scientists from the University of Hawai`i have recently made many submersible dives to the volcano and deployed instruments on its summit to study Lo`ihi in much greater detail.
The summit of Lo`ihi is marked by a caldera-like depression 2.8 km wide and 3.7 km long. Three collapse pits or craters occupy the southern part of the caldera; the most recent pit formed during an intense earthquake swarm in July-August 1996. Named Pele’s Pit, the new crater is about 600 m in diameter and its bottom is 300 m below the previous surface! Like the volcanoes on the Island of Hawaii, Lo`ihi has grown from eruptions along its 31-km-long rift zone that extends northwest and southeast of the caldera.
Height Above Sea Floor
Lo`ihi is built on the seafloor that slopes about 5 degrees beneath the seamount. Lo`ihi’s northern base is 1,900 m below sea level, whereas its southern base is 4,755 m below sea level. Thus, the summit is about 931 m above the seafloor as measured from the base of its north flank and 3,786 m above the seafloor as measured from the base of its south flank.
The name Lo`ihi means “long” in Hawaiian and was introduced in 1955 to describe the elongate shape of the seamount.
Most Recent Activity
Earthquake Swarm (>4,000 events), July 16-August 9, 1996
Hawaiian Volcano Stage
In transition between pre-shield and shield stage
Lo`ihi Seamount Information
Lo`ihi page, maintained by the Hawaii Center for Volcanology, School of Ocean and Earth Science and Technology, University of Hawai`i in Manoa.
Summary of 1996 Activity
Description of the intense earthquake swarm in July-August 1996 and the changes observed in Lo`ihi’s summit caldera; prepared by scientists of the Hawai`i Center for Volcanology, School of Ocean and Earth Science and Technology, University of Hawai`i Manoa. More than 4,000 earthquakes were recorded by HVO’s seismic network during this swarm.
Summary of Lo`ihi activity reported in the monthly Bulletin of the Global Volcanism Network, Smithsonian Institution. All information contained in these reports is preliminary and subject to change.